A building permit is needed for any pool addition. Staff will review the application to see if the proposed location impacts any wetland buffers, or is in the historic district, and you will be notified of the next steps if those regulations apply. Swimming pools are treated as accessory structures and need to meet setbacks within their Zoning District. 

A building permit is needed for a shed, or accessory structure except if it meets the following criteria (Section 10.811.60):

Any lot containing one or two dwelling units is permitted to construct and maintain a one-story detached accessory structure used as a tool or storage shed, playhouse, treehouse, or similar use per dwelling unit on the property, with a square footage not greater than 120 square feet. Accessory structures permitted shall not require any permit and shall be generally exempt from all provisions of the Zoning Ordinance except Article 10, Environmental Protection Standards, Section 10.516.30, Corner Lot Vision Obstruction, and Section 10.630 Historic District.

No accessory building, structure or use shall be located in any required front yard, or closer to a street than the principal building (Zoning Ordinance - Section 10.571) and all accessory buildings and structures shall be included in the computation of building coverage (Zoning Ordinance Section 10.574). Staff will review the building permit application to see if the proposed location impacts any wetland buffers, or is in the historic district, and you will be notified of the next steps if those regulations apply. All accessory structures are required to meet the setbacks of the Zoning District where they are located.  

1. An accessory building or structure not more than 10 feet in height and not more than 100 square feet in area shall be set back at least 5 feet from any lot line (Section 10.573.10). 
2. An accessory building or structure more than 10 feet in height or more than 100 square feet in area shall be set back from any lot line at least the height of the building or the applicable yard requirement, whichever is less (Section 10.573.20). 

Each application for a potential ADU is unique. We encourage you to come in and meet informally with the Planning Staff to discuss before making a formal application.  

There are two types of ADU – Attached and Detached – that can be created on a single-family property.  

1. Attached: An Attached ADU is conversion of interior space, an addition to the side or on a single-family residence. Interior renovations will require Administrative Approval. Additions will require Planning Board approval through a Conditional Use Permit.  
2. Detached: A Detached ADU will require Planning Board approval through a Conditional Use Permit. 

Staff will review each application and determine what the permitting process will require. After our informal meeting and if you decide to create an ADU, a building permit application must be made. This can be done using the online permitting program OpenGov. Planning and Sustainability staff will then work with you on the permitting process, making requests for any additional information if required. 

Depending on the height and location of a retaining wall, zoning review and a building permit may be required.  Please contact the Planning & Sustainability Department at 603-610-7216 or the Inspections Department at 603-610-7243 for a preliminary review of your retaining wall. 

We may have a subdivision or site plan on file for your property. It is unlikely that we will have a residential plot plan on file in the Planning Department, but you may want to make an appointment to review our files. Please contact the Planning Department at (603) 610-7216 and we can determine what we may have on file for your property. For review of the Inspections Department files please contact them at (603) 610-7243. 

You can find your Zoning District by searching for your property on MapGeo. Type in your address in the “Property Quick Search” box in the upper right corner of the map. Click on the “Themes” layer and toggle on “Zoning”. The legend will indicate which zone or zones your property is located in.  

The Zoning Ordinance outlines the use requirements for each zoning district in Section 10.440 - Table of Uses and the dimensional requirements in Article 5 and Section 10.521 - Table of Dimensional Requirements.  

If you need more assistance with the specific zoning requirements for your project please inquire with the Planning and Sustainability Department staff at (603) 610-7216.

A Land Use Permit Application is required for projects that require land use review by Planning Department staff and those that involve new construction, an addition or expansion of an existing building, home occupations, or any exterior renovations of properties located in the Historic District, as well as for any projects that require approval from the City's land use boards (Planning Board, Historic District Commission, and Zoning Board of Adjustment) including subdivisions, site plan review, conditional use permits, variances, special exceptions, and historic district commission certificates of approval. Please click here for more information on land use applications, forms and fees. For Building Permit requirements see the Inspection Department FAQs.

Please see the following reference guide for fences in the City of Portsmouth here.

The Planning and Sustainability Department (and Portsmouth City Hall) is open Monday 8:00AM - 6:00PM, Tuesday-Thursday 8:00AM - 4:30PM and Friday 8:00AM - 1:00PM. We welcome you to stop by our office on the third floor of City Hall at 1 Junkins Avenue during business hours, call us at 603-610-7216 or email planning@cityofportsmouth.com.